General Electric is shifting the strategy in its $17 billion-a-year health equipment and technology business, seeking to broaden its reach with more lower-cost products.

In an article in the New England Journal of Medicine, two leading researchers warn that the entry of big companies like Microsoft and Google into the field of personal health records could drastically alter the practice of clinical research and raise new challenges to the privacy of patient records. The authors, Dr. Kenneth Mandl and Dr. Isaac Kohane, are long-time proponents of the benefits of electronic patient records to improve care and help individuals make smarter health decisions.